large-scale enterprises so expensive that they are not likely to gain approval in any currently foreseeable funding environment. Long delays between large investments and significant returns make the financial burden still less attractive. The crux of these difficulties is the apparent need to carry fully manufactured machinery and equipment to generate useful output such as oxygen, water, or solar cells in situ. The Group decided to see if the feasibility of certain large-scale projects could be enhanced by using machines or machine systems that are able to reproduce themselves from energy and material resources already available in space. Such devices might be able to create a rapidly increasing number of identical self-replicating factories which could then produce the desired finished machinery or products. The theoretical and conceptual framework for self-reproducing automata, pioneered by von Neumann three decades ago, already exists, though it had never been translated into actual engineering designs or technological models.
The difference in output between linear and exponentiating systems could be phenomenal. To demonstrate the power of the self-replication technique in large-scale enterprises, the Telefactors Working Group assumed a sample task involving the manufacture of 106 tons of solar cells on the Moon for use in solar power satellites. A goal of 500 GW generating capacity - to be produced by entirely self-contained machinery, naturally occurring lunar materials, and sunlight for energy - was established. From an initial investment estimated at $1 billion, to place a 100-ton payload on the surface of the Moon, a nonreplicating or "linear" system would require 6000 years to make the 106 tons of solar cells needed - clearly an impractical project - whereas, a self-replicating or "exponentiating" system needs less than 20 years to produce the same 106 tons of cells (fig. 1.2, Bekey, 1980).
The Working Group concluded that replicating machine systems offer the tantalizing possibility in the near future that NASA could undertake surprisingly ambitious projects in space exploration and extraterrestrial resource utilization without the need for unreasonable funding requests from either public or private sources. In practice, this approach might not require building totally autonomous selfreplicating automata, but only a largely automated system of diverse components that could be integrated into a production system able to grow exponentially to reach any desired goal. Such systems for large-scale space use would necessarily come as the end result of a long R&D process in advanced automation, robotics, and machine intelligence, with developments at each incremental stage finding wide use both on Earth and in space in virtually every sphere of technology.
The Telefactors Working Group, believing that robotics, computer science, and the concept of replicating systems could be of immense importance to the future of the space program, recommended that NASA should proceed with studies to answer fundamental questions and to determine the most appropriate development course to follow.
1.2.3 Pajaro Dunes Symposium on Automation and Future Missions in Space (1980)
Because of the burgeoning interest in machine intelligence and robotics within NASA, the decision was made in September 1979 to fund an automation feasibility study to be conducted the following year as one of the annual joint NASA/ASEE Summer Study programs. To help provide the Summer Study with a set of futuristic goals and possibilities, an interactive symposium was organized by Robert Cannon at the request of Robert Frosch to take place the week before the opening of the summer session. During 15-22 June 1980, 23 scientists, professors, NASA personnel, and science fiction authors gathered at Pajaro Dunes near Monterey, California, to consider two specific questions: (1) What goals involving self-replicating telefactors might NASA possibly pursue during the next 25, 50, or 100 years, and (2) what are the critical machine intelligence and robotics technology areas that need to be developed? (Proceedings of the Pajaro Dunes Workshop, June 1980, unpublished).
A large number of highly imaginative missions were discussed, including automatic preparation of space colonies, an automated meteor defense system for the Earth, terrestrial climate modification and planetary terraforming, space manufacturing and solar power satellites, a geostationary orbiting pinhole camera to permit high-resolution solar imaging, lunar colonies, a Sun Diver probe capable of penetrating and examining the solar photosphere, advanced planetary surface exploration, and so forth. However, Workshop participants selected four missions they regarded as most significant to NASA's future and to the development of advanced automation technology:
Mission I - Very Deep Space Probe - highly automated for Solar System exploration and eventually to be extended to include interstellar missions capable of searching for Earthlike planets elsewhere in the Galaxy
Mission II - Asteroid Resource Retrieval - includes asteroids, jovian satellites and lunar materials that will use mass drivers, nuclear pulse rockets, etc., for propulsion
Mission III - Hazardous Experiment ("Hot Lab") Facility - an unmanned scientific laboratory in geostationary orbit with isolation necessary to safely handle such dangerous substances as toxic chemicals, high explosives, energetic radioisotopes, and genetically engineered biomaterials
Mission IV - Self-Replicating Lunar Factory - an automated unmanned (or nearly so) manufacturing facility consisting of perhaps 100 tons of the proper set of
